Ventilating-fan.



F. R. KUNKEL.

VENTILATING FAN.

APPLIUATION FILED JUNE 12, 1905.

N WITNESS ES: 1 INVENTOR zfiwy/ @fm W fiscal-A, TORNEY FRED R. ,KUNKEL, OF- WILKINSIBURG, PENNSYLVANIA.

V'ENTIIlATING-FAN.

- Specification of I'etters Patent. .Patented Sept. 6, 1910.

Application filed June 12; 1905. Serial No. '264,8 68- To all whomu' may concerns Be it Iknown. that/I, FRED R. KUNKEL, a

citizen of-the United States and a resident of WiIkinsbui-g, in'the county of Allegheny and State-of Pennsylvania, have invented a newfl'and; useful Improvement in Ventilating-Fans, of which the following is a specification.

My invention relates to fans for ventilating purposes and it has for its object to so improve the form of fan blades that the velocity of the air'that is delivered: from the fanmay be the same at all distances from its alxis of-rotation Neglecting the-efl'ect of friction, the ve- Tloc'ity of the air that'is delivered: from a'fan" I at any; radius normally to the plane of rotationisroport-ional to the product of the "length. of that radius, and the tangent of the an leformedbetween the plane of rota- ?t'ion" '.o the fan and a tangent line to the delivering edge of a fan blade at the extremity ofthe radius and at right angles to the radius. i t

My invention fan blades that this product, and consequ'efitly" yelocity of the air delivered, -may approximately constantv at all distances the axis of rotation of the fan, eddy currents and other energy-wasting disturbances of the'air being thereby avoided I, have found that'the tangent of the angle which a tangent line to a blade at its receiving edge should make with the plane of-'rotation for most advantageous and effective operation is approximately one-half thetangent of the anglewhich a tangent line to the blade at its disbharge edge'makes.

with theplane of rotation, the said tangent linesbe'ing perpendicular to radii of the fan.

Accordingly my invention consists further-in shaping the blades so that the tangents of the angles formedby tangent lines to the receiving edges shall be approxi- "mately one-half the tangents of the angles formed by tangent lines to the delivering edges at; corresponding distances from the anis'fof/rotationand so that the product of i the radii-and the tangents of the" angles -:formed between tan ent'lines to thereceiv-v ing' edges and'the p ane of rotationvmay be approzgiinately constant, the said tangent;

liin s 'bi'ngagain perpendicular to radii of t eiger.

sMy invention consists further inso' shapconsists in so. forming the locity of the air delivered from the ends of" the blades graduallyreduces to zero at the extremities, eddy currents at these locations and noise incident *to the operation of the fan being in this manner minimized.

' Myil-invention is illustrated in the accompanying drawing, Figure 1. of which is a yiew in front elevation of a fan constructed in accordance therewith and Fig. 2 is an end View of one blade of the fan shown in Fig. 1. i

Rigidly secured, to arms 1 of a hub 2 that is adapted'to be mounted'upon the armature shaft of an electric motor '(not shown) or that is adaptedio be otherwise'rotatably moimtedfarerffari blades?) having warped surfaces. 5

In' a'ccbrdanceWith the above stated princ1ples,"each of the fan blades-is so formed formed between aline L 5 drawn tangent to'the'blallle 'at' aipoint 6 and perpendicular to the radius terminating at the point 6 and a line 7%8 th at is drawn parallel to the planeofi rotation of the blade, and'tli distion' shall' be constantly equal to the product of corresponding quantities at: any other point on the same edg'e ofl the "blade as the point 6'. For instanoe t hefl product which a that the product of the tangent of the angle 'tazice 'ofi the point 6 from the axisiof rota- I includes the tangentalof the angle formed between the line Laana-ithanne i awhich is drawn tangent to the blade at the point 6 which is near ,the outer extremity there.- of, is equal to the product which includes the tangent of the angle formed between the line 78 and a line 9- 10 that isdrawn tangent to the discharge edge of the blade and perpendicular tot-he radius terminating at a point 11, which is located nearer the axis of rotation than the point 6. This product should remain constant regardless of the distance from the axis of rotation of the pointen thefiischarge edge of the 1 blade to which the tangent line is drawn.

The tangent of the angle formed between the line 78 and a line 12-13 that is drawn tangent to the receiving edge of the blade and perpendicular to the radius terminating 4 at a point 14: which is located near the outer extremity of the blade and at the same distance from theaxis ofrot-ation as the point 6, should be one-half the tangent of the angle formed between the lines 78 and 4l5. The blade is so constructed that the tangents of the angles formed by tangents to the receiving edges of the blade are constantly equal to one-half the tangents of the corresponding angles at the discharge edge of the blade.

In order to further reduce the eddy currents and the noise incident to the operation of the fan the outer ends 15 of the blades may be rounded as shown so that the velocity of the air delivered by the fan gradually decreases to zero from the points 16 toward the tips 17. Of course, the rounded end portions of the blades do not fulfil the same' these principles are observed. With the blades constructed as set forth, substantially all of the air delivered by the fan is delivered in a direction perpendicular to the plane of rotation, a result that is highly desirable in many classes of service.

I claim as my invention: I

1. A rotatably mounted fan blade which is soformed that the products of the speeds of travel of points on the'discharge edge of ion in Letters Patent No. 969,707.

Correct the blade and the tangents of angles formed between the plane of rotation and lines tangent to. the blade and perpendicular to the radii terminating at those points may be approximately constant.

2. A rotatably mounted fan blade, having a warped surface which is so shaped that the tangents of the angles formed between the plane of rotation and lines tangent to the blade at the discharge edge and to the circles of'rotation may be constantly and approximately equal to twice the tangents of the corresponding angles formed by lines tangent to the blade at the receiving edge and to the circles ofrotation. a 3. A rotatably mounted fan blade which is so formed that the products of the distances of points on the discharge edge of the blade from the axis of rotation and the tangents of the angles formed between the plane of rotation and lines tangent to the lade and to the circles of rotation at those points may be approximately constant, and. also so that the tangents of the anglesformedbetween the plane of rotation and lines tangent lines to corresponding points on the re' ceiving edge of the blade.

4. A rotatably mounted fan blade, having a warped surface which ,is so shaped that,

-gent to the discharge edgeof the blade and i the tangents of the angles formed between the plane of rotation and lines tangent to the blade at the discharge edge and to the circles of rotation may be constantly and approximately equal to twice the tangents of the corresponding angles formed by similar tangent lines to the blade at the receiving edge and the outer extremity of which is rounded.

In testimony whereof, I have hereunto subscribed my name this 6th day of June 1905.

FRED R. KUNKEL.

Witnesses:

Gno. D. PARsLnY, J r.,' BIRNEY HINES.

It is hereby certined that Letters Patent No. 969,707, granted September 6, 1910, upon the application of Fred R. Kunkehjof Wilkinsburg, l?ennsylvania,'tor an improvement 'in Ventilating-Fans, were erroneously issued to said inventor, whereas they should have been issued to Westinghouse Electric (2' Manufacturing Company}, a corporation of Pennsylvania, as owner of the entire interest in said invention, asshown by the records of assignments in this oflice; andthat the said Letters Patent should be read with this correctipn therein that the same may conform to the record of the'case in the Patent Otfice.

Signed and sealed this 27th day of September, A. D.,1910.

C. C. BILLINGS, Acting Commissioner of Patents.

receiving edges of the blade are constantly equal to one-half the tangents of the corresponding angles at the discharge edge of the blade.

In order to further reduce the eddy currents and the noise incident to the operation of the fan the outer ends 15 of the blades may be rounded as shown so that the velocity of the air delivered by the fan gradually decreases to zero from the points 16 toward the tips 17. Of course, the rounded end portions of the blades do not fulfil the same' these principles are observed. With the blades constructed as set forth, substantially all of the air delivered by the fan is delivered in a direction perpendicular to the plane of rotation, a result that is highly desirable in many classes of service.

I claim as my invention: I

1. A rotatably mounted fan blade which is soformed that the products of the speeds of travel of points on the'discharge edge of ion in Letters Patent No. 969,707.

Correct the blade and the tangents of angles formed between the plane of rotation and lines tangent to. the blade and perpendicular to the radii terminating at those points may be approximately constant.

2. A rotatably mounted fan blade, having a warped surface which is so shaped that the tangents of the angles formed between the plane of rotation and lines tangent to the blade at the discharge edge and to the circles of'rotation may be constantly and approximately equal to twice the tangents of the corresponding angles formed by lines tangent to the blade at the receiving edge and to the circles ofrotation. a 3. A rotatably mounted fan blade which is so formed that the products of the distances of points on the discharge edge of the blade from the axis of rotation and the tangents of the angles formed between the plane of rotation and lines tangent to the lade and to the circles of rotation at those points may be approximately constant, and. also so that the tangents of the anglesformedbetween the plane of rotation and lines tangent lines to corresponding points on the re' ceiving edge of the blade.

4. A rotatably mounted fan blade, having a warped surface which ,is so shaped that,

-gent to the discharge edgeof the blade and i the tangents of the angles formed between the plane of rotation and lines tangent to the blade at the discharge edge and to the circles of rotation may be constantly and approximately equal to twice the tangents of the corresponding angles formed by similar tangent lines to the blade at the receiving edge and the outer extremity of which is rounded.

In testimony whereof, I have hereunto subscribed my name this 6th day of June 1905.

FRED R. KUNKEL.

Witnesses:

Gno. D. PARsLnY, J r.,' BIRNEY HINES.

It is hereby certined that Letters Patent No. 969,707, granted September 6, 1910, upon the application of Fred R. Kunkehjof Wilkinsburg, l?ennsylvania,'tor an improvement 'in Ventilating-Fans, were erroneously issued to said inventor, whereas they should have been issued to Westinghouse Electric (2' Manufacturing Company}, a corporation of Pennsylvania, as owner of the entire interest in said invention, asshown by the records of assignments in this oflice; andthat the said Letters Patent should be read with this correctipn therein that the same may conform to the record of the'case in the Patent Otfice.

Signed and sealed this 27th day of September, A. D.,1910.

C. C. BILLINGS, Acting Commissioner of Patents.

Correction in Letters Patent No. 969,707.

It hereby certlned that Letters Patent No. 969,707, granted September 6, 1910,

"upon the application of Fred R. Kunkelrof Wilkinsburg, Pennsylvania, for an improvement in Ventilating-Fans, were erroneously issued to said inventor,

whereas they should have been issued to Westinghouse Electric d2 lllmmfactu'rz'ng Company a corporation of PennsyZv/mia, as owner of the entire interest in said invention, as shown by the records of assignments in this oflice; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day of September, A. D., 1910.

C. C. BILLINGS,

[SEAL] Acting Commissioner of Patents. 

